Exceptional is new normal: Experts break down anti-science tropes on extreme weather

Exceptional is new normal: Experts break down anti-science tropes on extreme weather

Weather and climate are separate things and, yes, climate change is often the underlying influence of extreme weather we see around the world. It increases intensity and frequency, say two Calgary experts.

The intensity of the Australian wildfire, followed by flash flooding in other parts of the country. Military called in to deal with multi-day Newfoundland weather event like none in recent memory. One-in-100-year flood in Calgary in 2013.

  • Watch University of Calgary climatologist Shawn Marshall stitch together some of the extreme weather events we've seen recently, in the video below.

A common thread between these and other extreme weather events is climate change, which has increased ambient temperatures, making extreme weather as a whole more intense and more frequent.

"If you see what's going on in Newfoundland right now and hear some of the stories, a lot of people don't have this in living memory," University of Calgary climatologist Shawn Marshall told CBC Calgary News at 6.

"It comes down to statistical distributions. If you picture a normal curve where you have extreme minima and maxima on either end, climate change shifts that whole distribution and that changes the frequencies."

He says it could be the economic cost of cleaning up that might drive a change in beliefs and actions.

Clockwise from top left: CP/AP/CP/AP
Clockwise from top left: CP/AP/CP/AP

"The costs associated with that could hammer us, could cripple us pretty hard," Marshall said.

"This is what the future looks like, more and more commonly. That's very disruptive, very expensive. What used to be exceptional is becoming normalized. It's not necessarily going to be easy for us."

Israel Dunmade, an associate professor in Mount Royal University's earth and environmental sciences department, says that despite tweets and statements by influencers whenever a cold stretch hits, weather and climate are not the same thing.

Andrew Vaughan/The Canadian Press
Andrew Vaughan/The Canadian Press

"Weather is for a short period. Climate is over a long period, usually 30 to 35 years average," Dunmade told CBC News.

"Over a long period of time, we are seeing from anthropogenic activities, our economic activities, an increase in ambient temperature. Over the years, as a result of that increasing temperature, it has led to the current climate change."

That increase makes things drier, so wildfires burn more often and with greater intensity, he said.

Wind plays a factor, too.

"Increasing temperature increases the capacity of the wind to carry more water. So instead of rainfall coming down, it will be carried to other places. That's why you find more dryness, and more incidents of a lot of fire breaking out," Dunmade said.

Submitted by Israel Dunmade
Submitted by Israel Dunmade

It also melts ice, which contributes to flooding. Again, more often and more intense.

When your uncle argues that there has always been extreme weather, therefore climate change isn't a thing, Marshall has a response for that.

"It's pretty hard to always attribute severe weather to climate change, but there is no question that some of these events, especially Australia, have a huge climate change layer to them," Marshall said.

"Extreme weather has always happened … but when you add a bit of climate change, more energy, more moisture [in the] atmosphere to the mix, then you start to get things we have not seen before."

Siobhan Threlfall/The Associated Press
Siobhan Threlfall/The Associated Press

And that term used to describe the 2013 Calgary-area floods, a "one-in-a-100 year event," we might need to adjust it.

"Maybe becoming one in 20, one in 10 — that kind of frequency."

Still, Marshall is an optimist.

"Reversing it is going to take a long time — decades, maybe a couple generations — but I think it's possible," he said.

"I still hold out hope that, even in my lifetime, I will see it stabilize, I will see our emissions level off. It's really important to reach some equilibrium."